The present invention relates to a metal laminate cylinder head gasket formed by laminating multiple metal plates.
For a cylinder head gasket placed between a cylinder block and a cylinder head of an internal combustion engine, a well-known cylinder head gasket formed by laminating multiple metal plates includes means which fastens the laminated multiple metal plates so as to prevent the metal plates from moving with each other. Conventionally, there are various types of fastening means for the above-mentioned means, for example, means which connects the metal plates by folding back a tongue piece provided in the metal plate on one side to the other metal plate, to a portion which is not sandwiched between the cylinder block and the cylinder head in the laminated multiple metal plates; or means which connects the metal plates by fastening the laminated metal plates by folding back the tongue piece while controlling the increase of the thickness of the metal plates in a gasket face, or by spot welding at an arbitrary position. Also, in the gasket disclosed in Japanese Patent Publication No. 2004-239313, the multiple metal plates are fastened by a rivet at a cooling water jacket.
However, as the internal combustion engines have recently become small in size and light in weight, there arises a chance of relative deformation of the cylinder block and the cylinder head due to oscillation during operation of the internal combustion engines, or pressure variation inside a combustion chamber; or deformation due to heating, cooling and the like of the gasket. Accordingly, when the cylinder block and the cylinder head are relatively displaced even a little due to the above-mentioned deformations, a force is applied to move the multiple metal plates constituting the gasket out of alignment from each other. In this case, if a connecting force between the laminated metal plates by the spot welding, the rivet and the like is weak, the connection between the metal plates is released in the above-mentioned portion. Accordingly, the connecting force is required to improve in some measure, so that the cost increases as well. Also, even in the case that the multiple metal plates are connected by folding back the tongue piece, misalignment between the metal plates and the like might occur if the connecting force between the respective metal plates is not improved by improving the strength of the tongue piece, or increasing the number of tongue pieces, so that the cost increases as well.
A technical feature of this invention is to form a misalignment preventing portion between the respective metal plates with simple means by using a projection from the surface of the laminated metal plates in a position corresponding to the cooling water jacket of the metal laminate cylinder head gasket which is structured by laminating the multiple metal plates.
Moreover, a specific technical feature of the invention is to form a simple misalignment preventing portion which eliminates the misalignment by fastening each metal plate as follows. The cylinder block is more easily deformed in a direction perpendicular to an arranging or longitudinal direction of multiple cylinder bores, so that the laminated multiple metal plates are strongly retained so as not to have the misalignment in a direction perpendicular to the arranging or longitudinal direction of the cylinder bores wherein the cylinder block is easily deformed. Also, the laminated multiple metal plates include a configuration wherein a restoring force acts on the joint surfaces of the metal plates in the arranging or longitudinal direction of the cylinder bores.
Further objects and advantages of the invention will be apparent from the following description of the invention.